performance goals and indicators will help determine needs for personnel training and development (U.S. Department of Education, October 1997).
Students with Disabilities: Who Qualifies?
Describing appropriate assessment policies for students with disabilities is complicated by the wide variation in the characteristics of the 5 million students—10 percent of the school-age population—who qualify for special education services under the IDEA. Cognitive, physical, sensory, and behavioral disabilities are covered.
Educating One and All describes the diversity of this population and their school experiences (National Research Council, 1997):
- Although 13 disabilities are mentioned in the federal IDEA and defined in the regulations, 4 categories of disability account for about 90 percent of all special education students: speech or language impairment, serious emotional disturbance, mental retardation, and specific learning disabilities. The category of learning disabilities, by itself, accounts for more than half of all students identified for special education.
- Identification and classification practices vary widely from place to place. Inconsistencies are particularly common in distinguishing students with mild cognitive disabilities, such as learning disabilities and mild mental retardation, from students who are low achieving but may not have a specific disability. Identification practices and disability definitions vary so greatly, in fact, that a student who is identified in one of these categories in one school district may not be so identified in another (Shepard, 1989). Prevalence rates vary widely across jurisdictions (U.S. Department of Education, 1995). Practices for identifying students with disabilities also vary over time and thus can affect estimates of trends in prevalence rates. The responses of schools to financial incentives (such as increased funding based on the numbers of students who are classified as having a disability) also vary over time and can affect these trends.
- Students with disabilities also vary in terms of their educational experience. Over the past 20 years, students with disabilities have been participating to an increasing extent in general education classrooms and curricula. For example, as of 1993–1994, almost 75 percent of special